1. Technical Field
The present invention relates to a liquid ejection device for ejecting a liquid on an ejection medium that is supported by suction on a medium support unit.
2. Related Art
From the past, inkjet printers (hereafter referred to simply as “printers”) have been put to practical use as liquid ejection devices for ejecting ink as a liquid from a liquid ejection head onto paper as one type of ejection medium that is transported while being supported on a medium support unit, and forming an image containing text or graphics. With this type of printer, on a medium support surface that the medium support unit has, a plurality of indented recesses are arranged in the direction orthogonal to the transport direction of the paper so as to be separated from the paper supported on the medium support surface, and the paper is suctioned to the medium support surface by suction of the paper at the recesses using negative pressure given to these recesses.
With this kind of printer, there are cases when so-called “borderless printing” is performed, by which ink is ejected from the liquid ejection head onto the entire surface of the paper to form an image. With a printer that performs this kind of “borderless printing,” the ink ejected from the liquid ejection head is also ejected outside the paper to the recesses at which the paper side edge part (end part) is positioned. Then, for the medium support unit for which the recesses on which ink is ejected in this way are provided on the medium support surface, for example in Japanese Laid-Open Patent Application Publication No. 2010-137399, proposed is a constitution by which the interior of the medium support unit is separated into at least one negative pressure chamber further to the inside of the paper width direction than the recess (borderless port) in which the ink is ejected. With this arrangement, the negative pressure chamber is divided into a negative pressure chamber that gives negative pressure to the recess at which the end part of the paper is positioned to recover ink that went past the end part of the paper during borderless printing or ink mist that floats in conjunction with the ejecting of ink, and a negative pressure chamber that gives negative pressure to the recesses by which the paper is suctioned on the medium support surface further to the inside in the width direction than the end part of the paper. By doing this, disturbance of the air flow inside the negative pressure chamber that gives negative pressure to the recesses that are suctioning the paper is suppressed, and floating of the paper is inhibited by maintaining a designated negative pressure given to the recess that is suctioning the paper.